U.S. patent application number 10/937626 was filed with the patent office on 2005-08-04 for ftth system for broadcast/communication convergence using ieee 1394.
Invention is credited to Cho, Jae-Hun, Koh, Jun-Ho, Park, Jeong-Rok, Song, Kwan-Woong.
Application Number | 20050169632 10/937626 |
Document ID | / |
Family ID | 34806099 |
Filed Date | 2005-08-04 |
United States Patent
Application |
20050169632 |
Kind Code |
A1 |
Song, Kwan-Woong ; et
al. |
August 4, 2005 |
FTTH system for broadcast/communication convergence using IEEE
1394
Abstract
A broadcast/communication convergence system, and an FTTH (Fiber
To The Home) system that can accommodate broadcast signals of
various channels and variable band signals by converging broadcast
and communication signals and transmitting the converged broadcast
and communication signals using an IEEE 1394 transmission method
serving as a standard interface in the FTTH system for
broadcast/communication convergence. An OLT (Optical Line Terminal)
transfers a plurality of broadcast signals and a communication
signal received from external broadcast and communication providers
through a single optical signal (A). An ONU (Optical Network Unit)
receives the optical signal (A) from the OLT, separates the
received optical signal into the plurality of broadcast signals and
the communication signal, opto-electrically converts the plurality
of broadcast signals and the communication signal, switches the
converted broadcast signals subscriber by subscriber, combines the
converted communication signal with the switched converted
broadcast signals. The result is transferred to a corresponding
subscriber through a single optical signal (B). A gateway at each
subscriber is implemented by IEEE 1394 protocol to receive the
optical signal (B) from the ONU, separate the received optical
signal into the broadcast signals and the communication signal, and
transfer the broadcast signals and the communication signal to a
corresponding subscriber device.
Inventors: |
Song, Kwan-Woong;
(Seongnam-si, KR) ; Park, Jeong-Rok; (Suwon-si,
KR) ; Cho, Jae-Hun; (Suwon-si, KR) ; Koh,
Jun-Ho; (Suwon-si, KR) |
Correspondence
Address: |
CHA & REITER, LLC
210 ROUTE 4 EAST STE 103
PARAMUS
NJ
07652
US
|
Family ID: |
34806099 |
Appl. No.: |
10/937626 |
Filed: |
September 9, 2004 |
Current U.S.
Class: |
398/72 |
Current CPC
Class: |
H04H 20/77 20130101;
H04J 14/0232 20130101; H04Q 11/0067 20130101; H04J 14/02 20130101;
H04J 14/0226 20130101; H04J 14/0247 20130101; H04Q 2011/0064
20130101; H04J 14/0282 20130101; H04J 14/0252 20130101 |
Class at
Publication: |
398/072 |
International
Class: |
H04J 014/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 3, 2004 |
KR |
2004-7046 |
Claims
What is claimed is:
1. An FTTH (Fiber To The Home) system for broadcast/communication
convergence, comprising: an OLT (Optical Line Terminal) for
transferring a plurality of broadcast signals and a communication
signal received from external broadcast and communication providers
through a single optical signal (A); an ONU (Optical Network Unit)
for receiving the optical signal (A) from the OLT, separating the
received optical signal into the plurality of broadcast signals and
the communication signal, opto-electrically converting the
plurality of broadcast signals and the communication signal,
switching the converted broadcast signals subscriber by subscriber,
combining the converted communication signal with the switched
converted broadcast signals, and transferring a resulting combined
converted communication signal and switched converted broadcast
signals to a corresponding subscriber through a single optical
signal (B); and a gateway at each subscriber for receiving the
optical signal (B) from the ONU, separating the received optical
signal into the broadcast signals and the communication signal, and
transferring the broadcast signals and the communication signal to
a corresponding subscriber device, wherein a connection between the
ONU and the gateway at each subscriber is implemented by IEEE
(Institute of Electrical and Electronics Engineers) 1394
protocol.
2. The FTTH system according to claim 1, wherein the ONU comprises:
a receiving/demultiplexing unit for receiving the optical signal
(A) from the OLT, separating the received optical signal into the
plurality of broadcast signals and the communication signal, and
demultiplexing the plurality of broadcast signals channel by
channel; a broadcast/communication data switching unit for
switching the broadcast signals demultiplexed by the
receiving/demultiplexing unit subscriber by subscriber, and
switching a downstream communication signal received from the
receiving/demultiplexing unit and an upstream communication signal
received from the gateway; and a first IEEE 1394 data controlling
and transmitting/receiving unit for converting the switched
broadcast signals and the downstream communication signal into IEEE
1394 data to transmit the IEEE 1394 data, and receiving IEEE 1394
data from the gateway.
3. The FTTH system according to claim 2, wherein the first IEEE
1394 data controlling and transmitting/receiving unit comprises: an
LLC (Link Layer Controller) coupled to each subscriber for
converting the switched broadcast signals and the downstream
communication signal into IEEE 1394 data; a PHY (PHYsical layer
controller) coupled to the LLC coupled to each subscriber for
carrying out IEEE 1394 interfacing; an optical transceiver coupled
to the PHY coupled to each subscriber for transmitting the IEEE
1394 data to the gateway; and a microprocessor coupled to the LLC
coupled to each subscriber for controlling flow of the broadcast
signals, providing a path of the communication signal and
processing a control signal.
4. The FTTH system according to claim 3, wherein the optical
transceiver coupled to each subscriber is an SFP (Small Form-factor
Pluggable).
5. The FTTH system according to claim 2, wherein the LLC coupled to
each subscriber includes the switched broadcast signals in
isochronous data of the IEEE 1394 data, and includes the downstream
communication signal in asynchronous data.
6. The FTTH system according to claim 3, wherein the LLC coupled to
each subscriber includes the switched broadcast signals in
isochronous data of the IEEE 1394 data, and includes the downstream
communication signal in asynchronous data.
7. The FTTH system according to claim 4, wherein the LLC coupled to
each subscriber includes the switched broadcast signals in
isochronous data of the IEEE 1394 data, and includes the downstream
communication signal in asynchronous data.
8. The FTTH system according to claim 2, wherein the LLC coupled to
each subscriber comprises: at least one buffer capable of being
controlled for buffering a broadcast signal of one channel among
the switched broadcast signals.
9. The FTTH system according to claim 3, wherein the LLC coupled to
each subscriber comprises: at least one buffer capable of being
controlled for buffering a broadcast signal of one channel among
the switched broadcast signals.
10. The FTTH system according to claim 4, wherein the LLC coupled
to each subscriber comprises: at least one buffer capable of being
controlled for buffering a broadcast signal of one channel among
the switched broadcast signals.
11. The FTTH system according to claim 1, wherein the gateway at
each subscriber comprises: a second IEEE 1394 data controlling and
transmitting/receiving unit for receiving the optical signal (B)
received from the ONU through IEEE 1394, and separating the
received optical signal into the switched broadcast signals and the
communication signal; and a broadcast/communication switch for
switching the broadcast signals and the communication signal
received from the second IEEE 1394 data controlling and
transmitting/receiving unit to a corresponding subscriber
device.
12. The FTTH system according to claim 2, wherein the gateway at
each subscriber comprises: a second IEEE 1394 data controlling and
transmitting/receiving unit for receiving the optical signal (B)
received from the ONU through IEEE 1394, and separating the
received optical signal into the switched broadcast signals and the
communication signal; and a broadcast/communication switch for
switching the broadcast signals and the communication signal
received from the second IEEE 1394 data controlling and
transmitting/receiving unit to a corresponding subscriber
device.
13. The FTTH system according to claim 3, wherein the gateway at
each subscriber comprises: a second IEEE 1394 data controlling and
transmitting/receiving unit for receiving the optical signal (B)
received from the ONU through IEEE 1394, and separating the
received optical signal into the switched broadcast signals and the
communication signal; and a broadcast/communication switch for
switching the broadcast signals and the communication signal
received from the second IEEE 1394 data controlling and
transmitting/receiving unit to a corresponding subscriber
device.
14. The FTTH system according to claim 4, wherein the gateway at
each subscriber comprises: a second IEEE 1394 data controlling and
transmitting/receiving unit for receiving the optical signal (B)
received from the ONU through IEEE 1394, and separating the
received optical signal into the switched broadcast signals and the
communication signal; and a broadcast/communication switch for
switching the broadcast signals and the communication signal
received from the second IEEE 1394 data controlling and
transmitting/receiving unit to a corresponding subscriber
device.
15. A method for providing broadcast/communication convergence in a
FTTH (Fiber To The Home) system, comprising the steps of: (a)
transferring a plurality of broadcast signals and a communication
signal received from external broadcast and communication providers
through a single optical signal (A) by an OLT (Optical Line
Terminal); (b) receiving the optical signal (A) from the OLT,
separating the received optical signal into the plurality of
broadcast signals and the communication signal, opto-electrically
converting the plurality of broadcast signals and the communication
signal, switching the converted broadcast signals subscriber by
subscriber, combining the converted communication signal with the
switched converted broadcast signals, and transferring a resulting
combined converted communication signal and switched converted
broadcast signals to a corresponding subscriber through a single
optical signal (B) by an ONU (Optical Network Unit); and (c)
receiving the optical signal (B) from the ONU, separating the
received optical signal into the broadcast signals and the
communication signal, and transferring the broadcast signals and
the communication signal to a corresponding subscriber device at a
gateway at each subscriber, wherein a connection between the ONU
and the gateway at each subscriber is implemented by IEEE
(Institute of Electrical and Electronics Engineers) 1394
protocol.
16. The method according to claim 15, wherein the ONU in step (b)
comprises: a receiving/demultiplexing unit for receiving the
optical signal (A) from the OLT, separating the received optical
signal into the plurality of broadcast signals and the
communication signal, and demultiplexing the plurality of broadcast
signals channel by channel; a broadcast/communication data
switching unit for switching the broadcast signals demultiplexed by
the receiving/demultiplexing unit subscriber by subscriber, and
switching a downstream communication signal received from the
receiving/demultiplexing unit and an upstream communication signal
received from the gateway; and a first IEEE 1394 data controlling
and transmitting/receiving unit for converting the switched
broadcast signals and the downstream communication signal into IEEE
1394 data to transmit the IEEE 1394 data, and receiving IEEE 1394
data from the gateway.
17. The method according to claim 16, wherein the first IEEE 1394
data controlling and transmitting/receiving unit comprises: an LLC
(Link Layer Controller) coupled to each subscriber for converting
the switched broadcast signals and the downstream communication
signal into IEEE 1394 data; a PHY (PHYsical layer controller)
coupled to the LLC coupled to each subscriber for carrying out IEEE
1394 interfacing; an optical transceiver coupled to the PHY coupled
to each subscriber for transmitting the IEEE 1394 data to the
gateway; and a microprocessor coupled to the LLC coupled to each
respective subscriber for controlling flow of the broadcast signals
and for providing a path for the communication signal, and for
processing a control signal.
18. The method according to claim 17, wherein the optical
transceiver coupled to each subscriber comprises an SFP (Small
Form-factor Pluggable).
19. The method according to claim 16, wherein the LLC coupled to
each subscriber includes the switched broadcast signals in
isochronous data of the IEEE 1394 data, and includes the downstream
communication signal in asynchronous data.
20. The method according to claim 17, wherein the LLC coupled to
each subscriber includes the switched broadcast signals in
isochronous data of the IEEE 1394 data, and includes the downstream
communication signal in asynchronous data.
Description
CLAIM OF PRIORITY
[0001] This application claims priority to an application entitled
"FTTH SYSTEM FOR BROADCAST/COMMUNICATION CONVERGENCE USING IEEE
1394", filed in the Korean Intellectual Property Office on Feb. 3,
2004 and assigned Serial No. 2004-7046, the contents of which are
hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a broadcast/communication
convergence system. More particularly, the present invention
relates to broadcasting in an FTTH (Fiber To The Home) system.
[0004] 2. Description of the Related Art
[0005] Current communication/broadcast subscribers have the choice
of employing a data service chosen from a plurality of data
services, such as a very high-speed Internet service, etc. via an
ADSL (Asymmetric Digital Subscriber Line), VDSL (Very High Bit-Rate
Digital Subscriber Line), Ethernet LAN (Local Area Network), cable
modem, etc., and may also employ broadcast services from at least
one of cable and satellite broadcasting based on an HFC (Hybrid
Fiber Coaxial) system. In other words, the subscribers have the
option to employ different mediums to receive the communication and
broadcast services. In cases where there are a combination of
protocols, a communication service rate is only several Mbps.
[0006] In order that high-speed, large-capacity
communication/broadcast services can be provided to the subscribers
to overcome limitations of older protocols, an FTTH (Fiber To The
Home) system for coupling an optical fiber to the subscriber's
premises or home is considered to be the best solution. FTTH
systems that provide high-speed, large-capacity
communication/broadcast services can be classified into one of a
PON (Passive Optical Network) and an AON (Active Optical
Network).
[0007] In order for broadcast/communication convergence to be
performed using the FTTH system, there has been proposed an FTTH
system for broadcast/communication convergence as shown in FIG. 1.
The FTTH system for broadcast/communication convergence shown in
FIG. 1 comprises an OLT (Optical Line Terminal) 300, an ONU
(Optical Network Unit) 400 and a gateway 500. The components for
broadcast/communication convergence perform the following
operations.
[0008] First, the OLT 300 receives digital broadcast information
100 and external data communication (VOD (Video On Demand),
Internet or etc.) information 200 via an external broadcasting
network, electro-optically converges received signals into an
optical signal, and transmits the optical signal using optical WDM
(Wavelength Division Multiplexing) via a WDM 106.
[0009] Moreover, the ONU 400 demultiplexes the WDM optical signal
received from the OLT 300 into broadcast and communication signals
via WDM 107, opto-electrically converts the broadcast and
communication signals, processes upstream information received from
a subscriber, and carries out a TDM (Time Division Multiplexing)
operation for the broadcast and communication signals selected user
by user, and transmits a TDM signal.
[0010] The gateway 500 carries out a TDDM (Time Division
Demultiplexing) operation for the TDM signal received from the ONU
400 and distributes a result of the TDDM operation service by
service. The gateway 500 optically transmits the upstream
information from the subscriber to the ONU 400.
[0011] Now, the components will be descried in detail. The OLT 300
shown in FIG. 1 includes: a broadcast MUX (Multiplexer) 101 for
receiving digital broadcast signals and multiplexing the received
digital broadcast signals; an optical transmitter 102 for
converting the multiplexed broadcast signals into an optical
signal; a communication switch 103 for receiving the Internet/VOD
information 200 to carry out a downstream switching operation for
the received Internet/VOD information 200 and receiving an upstream
communication signal from each subscriber to carry out an upstream
switching operation for the received upstream communication signal
to a network for the Intemet/VOD information 200; an optical
transmitter (Tx) 104 for converting a downstream communication
signal into an optical signal; an optical receiver (Rx) 105 for
receiving an upstream optical signal and converting the received
upstream optical signal into an electrical signal; and a wavelength
division multiplexer 106 for carrying out a WDM (Wavelength
Division Multiplexing) operation and transmitting a result of the
WDM operation.
[0012] Moreover, the ONU 400 shown in FIG. 1 includes: a wavelength
division demultiplexer 107 for separating an optical signal
received from the OLT 300 into broadcast and communication signals;
a broadcast DEMUX (Demultiplexer) 108 for separating the broadcast
signals received from the wavelength division demultiplexer 107 on
a broadcast channel-by-channel basis; a broadcast switch 109 for
switching the broadcast signals separated channel by channel
according to the subscriber's selection operation; a communication
switch 112 for switching a downstream communication signal
separated from the wavelength division demultiplexer 107 subscriber
by subscriber and switching an upstream communication signal
received from the subscriber to the OLT 300; time division
multiplexers 110-1 to 110-n for carrying out a TDM operation for
the broadcast and communication signals subscriber by subscriber;
and optical transceivers (Tx/Rx) 111-1 to 111-n for transmitting
the broadcast and communication signals multiplexed by the time
division multiplexers 110-1 to 110-n to respective subscribers (or
gateways) and transmitting upstream signals from the subscribers to
the communication switch 112 via the time division multiplexers
110-1 to 110-n.
[0013] Moreover, each gateway 500, as shown in the exploded view in
FIG. 1, includes: a transceiver (Tx/Rx) 113 for receiving a
downstream signal from the ONU 400 and transmitting an upstream
signal to the ONU 400; a time division demultiplexer 114 for
separating the broadcast and communication signals multiplexed by
the TDM operation; and a communication switch 115 for receiving the
communication signal from the time division demultiplexer 114 to
transmit the received communication signal to a communication unit
such as an Internet/PC (Personal Computer) 118 of the subscriber,
etc., and receiving an upstream signal from the communication unit
(such as the Internet/PC 118, etc.) to transmit the received
upstream signal to the ONU 400.
[0014] After receiving the broadcast signals transferred from the
time division demultiplexer 114, the subscriber decodes the
broadcast signals through an STB (Set-Top Box) 116, views the
broadcast on a digital TV (Television) 117, and can access the
network by transmitting and receiving the communication signals
sent through the Internet/PC 118.
[0015] The conventional FTTH system for broadcast/communication
convergence carries out a TDM operation for the broadcast and
communication signals to transmit a result of the TDM operation
according to a connection between the ONU 400 and the gateway 500,
and subsequently carries out a TDDM operation. However, the
conventional FTTH system has problems when accommodating items such
as a multi-channel broadcast signal or a broadband communication
signal.
[0016] The reason that the conventional FTTH system for
broadcast/communication convergence has problems accommodating
multi-channel broadcast signals or broadband communication signals
is that the FTTH system employs a TDM operation for multiplexing a
communication signal (e.g., Ethernet data) between the ONU 400 and
the gateway 500 at a subscriber side and broadcast signals selected
by the subscriber into one time frame, followed by transmitting a
result of the multiplexing. Here, the time frame is generated
through an FPGA (Field Programmable Gate Array). In this case, the
FPGA can accommodate only a 100-Mbps Ethernet signal and a maximum
of two HD (High Definition) channels because of the limitations of
its processing rate. In particular, the FPGA is designed so that it
can accommodate only fixed-length broadcast signals. For this
reason, the conventional FTTH system for broadcast/communication
convergence is not capable of accommodating broadcast signals based
on various standards (e.g., broadcast signals of various
wavelengths), and cannot accommodate three-channel broadcast
signals.
SUMMARY OF THE INVENTION
[0017] The present invention provides an FTTH (Fiber To The Home)
system for broadcast/communication convergence using IEEE
(Institute of Electrical and Electronics Engineers) 1394 that can
accommodate broadcast signals of various channels and variable band
signals by converging broadcast and communication signals and
transmitting the converged broadcast and communication signals
using an IEEE 1394 transmission method serving as a standard
interface in the FTTH system for broadcast/communication
convergence.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The above features and other advantages of the present
invention will be more clearly understood from the following
detailed description taken in conjunction with the accompanying
drawings, in which:
[0019] FIG. 1 is a block diagram illustrating an FTTH (Fiber To The
Home) system for broadcast/communication convergence as has been
previously proposed;
[0020] FIG. 2 is a block diagram illustrating an FTTH (Fiber To The
Home) system for broadcast/communication convergence using IEEE
(Institute of Electrical and Electronics Engineers) 1394 in
accordance with an aspect of the present invention;
[0021] FIG. 3 is a block diagram illustrating an ONU (Optical
Network Unit) included in the FTTH system for
broadcast/communication convergence using IEEE 1394 in accordance
with an aspect of the present invention; and
[0022] FIG. 4 shows an example of a data transmission cycle used in
the present invention.
DETAILED DESCRIPTION
[0023] Now, several aspects of the present invention will be
described in detail with reference to the annexed drawings. In the
drawings, the same or similar elements are denoted by the same
reference numerals even though they are depicted in different
drawings. For the purposes of clarity and simplicity, a detailed
description of known functions and configurations incorporated
herein will be omitted as it may obscure the subject matter of the
present.
[0024] FIG. 2 is a block diagram illustrating an FTTH (Fiber To The
Home) system for broadcast/communication convergence using IEEE
(Institute of Electrical and Electronics Engineers) 1394 in
accordance with an aspect of the present invention.
[0025] As shown in FIG. 2, the FTTH system for
broadcast/communication convergence using IEEE 1394 in accordance
with the present invention includes the components of the OLT 300
and the connection between the OLT 300 and the ONU 400 as in the
conventional FTTH system for broadcast/communication convergence
shown in FIG. 1. Therefore, a description of the identical
components and connection structures will be omitted.
[0026] Before a detailed description is given of a constitution of
the present invention, a description will be given of IEEE
1394.
[0027] IEEE 1394 is called "Firewire" as a standard of a serial bus
interface jointly created by Apple Computer, Inc. and Texas
Instruments, Inc. IEEE 1394 was conceived in 1986 and was
standardized on December 1995 by IEEE.
[0028] IEEE 1394 serves as a serial bus interface that enables a
maximum of 63 nodes to be coupled to each bus. Due to the fact that
IEEE 1394 gives a priority to isochronous data in processing
isochronous data/AV (Audio Visual) stream data mainly used for
transmitting multimedia information, and asynchronous data/control
and packet data used for transmitting communication or control
information, there is an advantage in that QoS (Quality of Service)
for multimedia data can be ensured in a home network. Moreover,
IEEE 1394a defines S100, S200 and S400 bit rates, and IEEE 1394b
defines optical mediums such as POFs (Plastic Optical Fibers), SMFs
(Single Mode Fibers), MMFs (Multi-Mode Fibers), etc., such that a
high bit rate of 3.2 Gbps can be ensured and hence it is predicted
that an effective solution for the home network and remote data
communication will be provided.
[0029] The FTTH system in accordance with the aspect of the present
invention employs the MMF or SMF as the transfer medium according
to the IEEE 1394b standard. The present invention shows an example
of the design of a low-priced light source.
[0030] Here, the low-priced light source can be selected according
to a transmission distance, transmission rate, price, etc. A
typical example of the low-priced light source used in the
conventional FTTH system is an SFP (Small Form-factor Pluggable).
Where the MMF is employed as the transfer medium in the SFP of an
output wavelength of 850 nm, an optical signal can be transmitted
up to a maximum of 3 Km at 1.25 Gbps. Accordingly, the FTTH system
using IEEE 1394 employs the SFP as the light source, because the
ONU 400 and the subscriber (or gateway 500) can be designed within
approximately 1.about.2 Km.
[0031] The currently commercialized IEEE 1394b supports a maximum
transmission rate of 800 Mbps. The IEEE 1394b standard defines a
transmission rate of up to 3.2 Gbps. For this reason, transmission
capacity of the FTTH system will be able to be improved using IEEE
1394 in the future as taught by the present invention.
[0032] FIG. 4 shows an example of a data transmission cycle used in
the present invention.
[0033] IEEE 1394 basically defines 125 us as one cycle 41, 42 or
43, and defines a transfer layer with a data rate of S100, S200,
S400, S800, S1600 or S3200. According to IEEE 1394, isochronous
data units 404, 405, 406 and 412 can occupy a maximum of 80% of one
cycle, while asynchronous data units 401, 402, 407, 408, 409 and
410 can occupy a total of 20% of one cycle. In the beginning of
each cycle 41, 42 or 43, a cycle start packet 403 or 411 is used to
indicate that a new cycle starts.
[0034] Because a transmission timing of the isochronous data is
first taken into account and the isochronous data is transmitted in
a transmission form appropriate for transmitting multimedia data,
the isochronous data is transmitted prior to the asynchronous data.
On the other hand, the asynchronous data can employ 20% of one
cycle, and is transmitted taking into account its transmission
quality.
[0035] Therefore, in accordance with the present invention, a
broadcast signal is assigned to the isochronous data, while a
communication signal (e.g., a zapping signal or a signal from an
NMS/EMS (Network Management System/Element Management System) or
etc. is assigned to the asynchronous data. Accordingly, the present
invention can perform a transmission operation based on
broadcast/communication convergence as in TDM (Time Division
Multiplexing) of the conventional FTTH system.
[0036] Moreover, a plurality of isochronous channels 404, 405 and
406 can be accommodated within a transmission cycle of 125 us in
IEEE 1394. Where the maximum transmission capacity is designed at
400 Mbps, the isochronous channels can consist of channels of
various lengths at a maximum of 300 Mbps if asynchronous data
transmission at 100 Mbps is assigned for use in the Ethernet.
[0037] For example, a maximum of 6 fixed-length broadcast channels
at 50 Mbps can be supported. In case of 27-Mbps broadcast channels,
11 channels can be transmitted to a single subscriber. Moreover, as
the length of each isochronous packet varies, data can be
transmitted according to various broadcast formats. Theoretically,
a maximum of 64 isochronous channels can be supported.
[0038] Thus, the FTTH system according to the present invention
provides a transmission technology or operation between the ONU 400
and the gateway 500 that is implemented using the IEEE 1394
transmission method in the inventive FTTH system, rather than an
implementation TDM through the FPGA as known heretofore.
[0039] As shown in FIG. 2, the ONU 400 includes: a wavelength
division demultiplexer 201 for separating an optical signal
received from the OLT 300 into broadcast and communication signals;
a broadcast DEMUX (Demultiplexer) 202 for separating the broadcast
signals received from the wavelength division demultiplexer 201 on
a broadcast channel-by-channel basis; a broadcast switch 203 for
switching the broadcast signals separated channel by channel
according to a subscriber's selection operation; a communication
switch 208 for switching a downstream communication signal
separated from the wavelength division demultiplexer 201 subscriber
by subscriber, and for transmitting an upstream communication
signal received from the subscriber to the OLT 300; LLCs (Link
Layer Controllers) 204-1 to 204-n for converting the broadcast and
communication signals switched subscriber by subscriber into IEEE
1394 data; IEEE 1394 PHYs (PHYsical layer controllers) 205-1 to
205-n responsible for IEEE 1394 interfacing; low-priced optical
transceivers (Tx/Rx) 206-1 to 206-n for transmitting the IEEE 1394
data to the gateway 500; and a microprocessor 207 coupled to the
LLCs 204-1 to 204-n for controlling flow of the broadcast signals
to provide a path for the communication signal and processing of a
control signal (e.g., channel zapping).
[0040] Moreover, each gateway 500 comprises: an optical transceiver
(Tx/Rx) 209 for optically transmitting and receiving light based on
IEEE 1394; a PHY (PHYsical layer controller) 210 for receiving IEEE
1394 data transferred through the low-priced optical transceiver
209; an LLC (Link Layer Controller) 211 for converting the IEEE
1394 data into the broadcast and communication signals; a decoder
212 for receiving and decoding the broadcast signals from the LLC
211 and providing the decoded broadcast signals to a digital TV
(Television); a communication switch 213 for receiving the
communication signal from the LLC 211 to transfer the received
communication signal to the subscriber and receiving an upstream
communication signal from the subscriber to transfer the received
upstream communication signal to the LLC 211; and a microprocessor
214 coupled to the LLC 211 for controlling flow of the broadcast
signals, providing a path for the communication signal, and for
processing a control signal (e.g., channel zapping).
[0041] Moreover, each subscriber is directly coupled to the LLC 211
using the STB supporting the IEEE 1394 standard to use the digital
TV. Where IEEE 1394 is not supported, the digital TV is used
through the decoder 212. Data service is received through the
communication switch 213 using the Internet/PC (Personal
Computer).
[0042] FIG. 3 is a block diagram illustrating the ONU 400 included
in the FTTH system for broadcast/communication convergence using
IEEE 1394 in accordance with another aspect of the present
invention.
[0043] As shown in FIG. 3, the ONU 400 in accordance with the
present invention comprises: a receiving/demultiplexing unit 31 for
receiving a signal from the OLT; a broadcast/communication data
switching unit 32 for switching the broadcast and communication
signals; and an IEEE 1394 data controlling and
transmitting/receiving unit 33 for transmitting and receiving IEEE
1394 data. It should be noted that units 31 and 32 could be
arranged somewhat differently than as shown in FIG. 3, as the
illustration is provided for explanatory purposes, and is not
intended to limit the invention to the arrangement shown.
[0044] According to this aspect of the present invention, the IEEE
1394 data controlling and transmitting/receiving unit 33 converts
data output from the broadcast switch 203 into an IEEE 1394
transmission frame and transmits the IEEE 1394 transmission frame
to the gateway 500 subscriber by subscriber. In order to perform
such functions, the ONU according to the present invention includes
the IEEE 1394 data controlling and transmitting/receiving unit 33
having IEEE 1394 LLCs 204-1 to 204-n, IEEE 1394 PHYs 205-1 to
205-n, SFPs 206-1 to 206-n, and a microprocessor 207.
[0045] Here, the LLCs 204-1 to 204-n include a predetermined number
of buffers adapted for being controlled and having a predetermined
number of data interfaces. Since each of the buffers included in
the LLCs 204-1 to 204-n is assigned to a single broadcast channel
(or MPTS (Multi-Program Transport Stream)), the number of buffers
corresponds to the number of acceptable broadcast channels (or
MPTSs).
[0046] Moreover, the microprocessor 207 coupled to the LLCs 204-1
to 204-n controls a flow of the broadcast signals, provides a path
of the communication signal and processes a control signal (e.g.,
channel-zapping, etc.). The operation of the microprocessor 207
typically conforms to a specification of the IEEE 1394
standard.
[0047] The PHYs 205-1 to 205-n enabling a beta output based on the
IEEE 1394a standard can directly drive light sources for various
subscribers such as a UTP (Unshielded Twisted Pair), a POF (Plastic
Optical Fiber), an SFP (Small Form-factor Pluggable), etc.
Preferably, the SFPs 206-1 to 206-n are used to ensure a
transmission distance between the ONU and the subscriber within 2
Km and a transmission bandwidth of a 400-Mbps class. The system can
be configured using various light sources such as an SFF (Small
Form Factor), a bidirectional transceiver, multiple sources, etc.
The optical transceivers (Tx/Rx) 206-1 to 206-n shown in FIG. 2 use
the SFPs 206-1 to 206-n shown in FIG. 3.
[0048] The subscriber gateway 500 employs an IEEE 1394
transmitting/receiving unit (e.g., the above-described low-priced
light source, etc.) as in the configuration of the ONU 400. The
gateway 500 is symmetric to the IEEE 1394 controlling and
transmitting/receiving unit of the ONU 400. This has been described
with reference to FIG. 2. Transceivers for IEEE 1394 data are
independently implemented subscriber by subscriber. In other words,
when an IEEE 1394 device is attached or removed where a network for
multiple channels using IEEE 1394 is implemented, an operation for
resetting a system is independently carried out in each subscriber,
such that no interference occurs. According to the implementation
of an independent IEEE 1394 transmission network, the IEEE 1394
transmission network can provide a sufficient communication
bandwidth and a plurality of high-quality broadcast channels.
[0049] As apparent from the above description, the present
invention can accommodate broadcast signals of various channels by
converging broadcast and communication signals and transmitting the
converged broadcast and communication signals using an IEEE
(Institute of Electrical and Electronics Engineers) 1394
transmission method serving as a standard interface in an FTTH
(Fiber To The Home) system for broadcast/communication
convergence.
[0050] Moreover, the present invention can accommodate variable
band signals by transmitting data through IEEE 1394.
[0051] Although the preferred aspects of the present invention have
been disclosed for illustrative purposes, those skilled in the art
will appreciate that various modifications, additions and
substitutions are possible, without departing from the spirit of
the invention or the scope of the appended claims.
* * * * *